T-Bone,
Rub is what you want to make of it. It will depend on the meat, the rub itself (large or small granules).
I find the time applied to the meat has more impact than the rubbing. Some things you want on overnight to they impart more flavor (beef) , and some you don't (pork).
My take is I don't use oils, mustards, anything like that to make the rub "stick". I've found, if I apply and let it sit, the salt will bring moisture to the top and then it works fine.
But both are methods that many people use.